Decision-making for treatment of metastatic breast cancer after the second line of chemotherapy was limited by the lack of established predictive factors of benefit for further chemotherapy regimens. Eribulin has emerged as the only single agent demonstrating an overall survival improvement in the third-line setting or beyond. The purpose of this study was to define the clinical profile of metastatic breast cancer participants achieving long-term benefit from chemotherapy with eribulin in the third-line setting or beyond.